The consultant who once warned that California’s richest residents poured millions into politics because they had something to gain is now helping billionaires fight a tax on their fortunes.

Ned Wigglesworth, who denounced the “billionaire boys’ club of politics” as a campaign finance reformer decades ago, is a key strategist behind Building a Better California, the political organization opposing Proposition 40. The November ballot measure would impose a one-time 5% tax on Californians worth at least $1 billion.

The campaign has already attracted major Silicon Valley funding. Google cofounder Sergey Brin alone has contributed more than $100 million to the group, while venture capitalist John Doerr and crypto billionaire Chris Larsen have also put money into committees fighting the tax. Building a Better California has reserved $87 million in advertising ahead of the vote, underscoring how quickly California’s wealth fight has become a high-dollar political contest.

It remains unclear what led Wigglesworth from opposing the political influence of California’s wealthy to helping them defeat a tax aimed at their fortunes. The San Francisco Standard described him as a “billionaire whisperer,” citing interviews with anonymous colleagues who portrayed him as a veteran of Sacramento lobbying. His LinkedIn profile lists him at several communications firms, including founding partner and CEO of Spectrum Campaigns for more than 10 years, and previously partner at Redwood Pacific Public Affairs, vice president at Goddard Claussen/West, and vice president at the California Medical Association. Wigglesworth did not respond to Fortune’s requests for comment.

His career arc reflects a long-running tension in California politics: the state has produced extraordinary concentrations of wealth and also has a political appetite for taxing that wealth, even as it relies on the people and companies that created it.

Gov. Gavin Newsom has also been caught in that tension. He opposes the billionaire tax, but has also pushed for reducing inequality, an issue that has become increasingly important for Democrats. Newsom has proposed higher taxes on the ultrawealthy at the federal level and said California needs to “democratize our economy” amid growing rhetoric about AI-related job loss.

As a campaign finance watchdog two decades before the billionaire tax proposal, Wigglesworth warned Californians about what happens when wealthy donors flood politics with cash. “There’s some very wealthy and powerful special interests who have enough at stake to spend 150 million bucks, to either defend their turf or improve their bottom line,” Wigglesworth said in 2005. “These people aren’t spending money out of some benevolent sense of improving societal good, improving the public good. This is about people fighting for their piece of the pie.”

“In other words,” Wigglesworth wrote in a 2007 Capitol Weekly column, “they give because they get.”

California’s wealth tax fight is a vivid test of that earlier thesis. Proposition 40 would apply to roughly 200 billionaires who lived in California as of Jan. 1, with a one-time levy equal to 5% of their wealth. Supporters say the measure could raise about $100 billion, with most of the money earmarked for health care after federal Medicaid cuts.

For the billionaires affected, however, the potential tax bills are enormous. Brin would reportedly owe $13 billion if the measure passes. He and fellow Google cofounder Larry Page moved out of California before the Jan. 1 cutoff and have since accumulated about $225 million in Miami real estate.

The proposal has also sparked debate over whether California risks driving away the people who pay a disproportionate share of its tax bill. Nearly half of the state’s personal income tax revenue comes from the top 1%. Newsom opposed the measure on those grounds. Venture capitalist Vinod Khosla said he has no plans to leave California, but warned that the state could permanently damage its tax base if wealthy residents depart.

The amounts involved today dwarf the spending Wigglesworth warned about more than 20 years ago. California’s 15 richest billionaires have poured more than $336 million into state and federal elections this year, with Brin, Marc Andreessen, Ben Horowitz and Larsen accounting for $331 million of that total.

This story was originally featured on Fortune.com